July 7th Severe Weather Outlook

July 7th Severe Weather Outlook
First we are going to start this off with saying that the majority of the day we expect to be under a CAPPED environment. .However..we anticipate this to break and for storms to effect the eastern PA region after 8 PM ..between 8 PM and up till 8 AM..
Also we are looking at a very HOT DAY! The temperatures and the humidity are going to be no joke. Do not go outside unless you have to go outside and make sure you drinking plenty of water (preferably FIJI water) ..
Temperatures today are going to be between the 80s and 100's.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F18_TMPF_2_M_ABOVE_GROUND.png
Dew points are going to be in the 60s and 70s
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F18_DPTF_2_M_ABOVE_GROUND.png
With the heat index near 110 degrees! Again this heat alone can be very dangerous without adding in the severe weather aspect. We have been talking about how this has the potential to be a decent event if we can become unCAPPED. Looking at the surface expected by Saturday evening at 8 PM
http://www.hpc.ncep.noaa.gov/basicwx/94fwbgus.gif
You have a very HOT and humid air mass coming into play and you have a very strong cold front coming thru the region. Whenever you have the clashing of two air masses with strong heating in place and strong cooling coming in you are setting the stage for what could be a decent severe weather potential.
Lets look at the parameters in place across the region..
CAPE is going to be 500 to about 4000 across the zone. Remember CAPE is convective available potential energy. You can view this like fuel being added to a fire depending on the rest of the parameters.
LIFT INDEX from 0 to about -6..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F24_PLI_30_0_MB_ABOVE_GROUND.png
SHEAR is going to be supportive of severe weather with 30-40 knots across the region , where the main focus will be today (further south tomorrow)
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F24_SHRM_500_MB.png
Now this is going to be where we are going to disagree with the Storm Prediction center when we look at the ENERGY HELICITY INDEX we see this:
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F24_EHI_3000_M.png
This shows EHI as high as 3-5 in Eastern and Central PA
HELICITY however is lower but still around 300 and actually increases in the overnight period.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F24_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/07/00/NAM_221_2012070700_F30_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png
So in addition to the winds and hail potential across the PA into NJ region we are going to go with a 2 % tornado chance..
If you are out and about keep an eye to the sky ..especially once we head towards evening time...

July 6th Severe Weather Outlook

July 6th Severe Weather Outlook
First we want to start this off by saying that the next two days it is going to continue to be HOT and in the east it will become perhaps unbearable on Saturday. A heat wave has been taking place from the central to the southeast and south central into the Mid Atlantic region and this is going to continue at least into Saturday. There after things will change.
Temperatures today across the areas mentioned above are going to be HOT. Temperatures will be from 80 once again into the 100's.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_TMPF_2_M_ABOVE_GROUND.png
In addition to the HOT temperatures it is going to be humid with dew points between 60 and 70 degrees.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_DPTF_2_M_ABOVE_GROUND.png
CAPE or Convective Potential Energy across the region will be from 500 to about 3500.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_CAPE_SURFACE.png
LIFT INDEX will be from 0 to about -8 depending on where you live across the two severe zones.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_PLI_30_0_MB_ABOVE_GROUND.png
The greatest SHEAR is going to be across the 15% zone which is expected to be to 60 knots across that zone.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_SHRM_500_MB.png
ENERGY HELICITY INDEX across the 15% region is as high as 3
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_EHI_3000_M.png
HELICITY is actually as high as 500 across the same general region..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/06/00/NAM_221_2012070600_F24_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png
At the surface we have a frontal system going across the northern tier of the USA with a low pressure area located over South Dakota.This turns into a cold front going across Lower Michigan.
http://www.hpc.ncep.noaa.gov/basicwx/91fwbgus.gif
This low pressure area will make its way off to the east northeast and serve as a trigger for severe weather along the stationary front..

Severe Weather outlook for July 4th Weather Discussion..

Severe Weather outlook for July 4th Weather Discussion.. If it sounds like a broken record in regards to temperatures..well that is really because it is. Before we get into temperatures ..we want to take the time to wish Everyone A Happy 4th of July that is in the USA! Temperatures once again are going to be on the hot side with high temperatures between 80 and into the 100's. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F18_TMPF_2_M_ABOVE_GROUND.png .. In addition to this we are talking about Dew points in the 60-70 range so it is going to be even hotter yet to the skin! Please drink plenty of water... http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_DPTF_2_M_ABOVE_GROUND.png ... CAPE across the region is 500-4000 depending on where you reside in the zone. Majority of PA is red in color meaning 3000 + ..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_CAPE_SURFACE.png...Ample LIFT across the region with the LI down to negative 11 ..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_PLI_30_0_MB_ABOVE_GROUND.png ... SHEAR is one thing lacking across PA at only about 25 knots and in other areas it is to 40 knots.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_SHRM_500_MB.png ... EHI is also high across E PA ..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_EHI_3000_M.png ... However..HELICITY is lacking .. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/04/00/NAM_221_2012070400_F24_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png .. At the surface... http://www.hpc.ncep.noaa.gov/basicwx/91fwbgus.gif A batch of mainly Non Severe storms is moving thru western PA and central PA at the present time. By 00z later tonight there will be a cold front approaching the region. http://www.hpc.ncep.noaa.gov/basicwx/94fwbgus.gif and another cold front will be crossing the Midwest area (guidance slowed this second front down which is why no severe happened in the mid west yesterday)..these frontal systems will be the trigger for severe weather potential.. In the Northeast we have some difference in the guidance..on one hand the NAM despite parameters lacks moisture.. http://raleighwx.americanwx.com/models/nam/00znam850mbTSLPp06024.gif On the other hand the GFS .. http://raleighwx.americanwx.com/models/gfs/00zgfs850mbTSLPp06024.gif ..So.. because it is a holiday we decided to use a blend this time of the guidance being the SREF/GFS and NAM has less weighting other then using it to show the parameters. As you can see GFS is not lacking in CAPE either..http://raleighwx.americanwx.com/models/gfs/00zgfsSurfaceCapeCINS024.gif Stay safe and Have a Happy 4th of July! We will be here all day after 12 noon to watch for any development of the storms!

Preview at July 4th Severe Potential

With the 4th of July and fireworks planned across the USA we are doing a day 2 map which is subject to change being that we are talking something that is 48 hrs. or more out. So no discussion will be released at this time...
It should be noted that SPC took the region out of a slight risk and only has a 5% zone now....

Severe Outlook For July 3rd 2012

Severe Outlook For July 3rd 2012

http://www.hpc.ncep.noaa.gov/basicwx/91fwbgus.gif
We are going to start off with looking at the surface map depicted as of 06 Z (2am) one hour from now. Low pressure in Canada with a cold front trailing to the Southwest to another low over the Dakotas. From the low in Canada extends a warm front to the south east. By 12 Z the warm front slips east a little and the cold front moves east a little.. By 18 Z the cold front is now approaching upper Michigan in the western side.. http://www.hpc.ncep.noaa.gov/basicwx/93fwbgus.gif  It will be this frontal system that will once again be the focus point for severe weather potential.
A look at the severe weather parameters across the area along with the temperatures.. Once again it is going to be a very HOT day across the vast majority of the country from the central states towards the east.  Temperatures are going to be from 80 to in the 100's once again..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/03/00/NAM_221_2012070300_F18_TMPF_2_M_ABOVE_GROUND.png
In addition to this the Dew Points will be in the 60-70 degree range which will make the air temperature feel even hotter. (Ready for winter yet? We are!)
CAPE or CONVECTIVE POTENTIAL ENERGY..
Anywhere from 500-4000 depending on where you are in the severe zone..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/03/00/NAM_221_2012070300_F24_CAPE_SURFACE.png
Lift Index is 0 to negative 10 depending once again on where you reside.
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/03/00/NAM_221_2012070300_F24_PLI_30_0_MB_ABOVE_GROUND.png
SHEAR
Greatest wind shear which is 50-70 knots is actually back over the Montana region. Elsewhere we are only looking at marginal shear of less then 30 to no more then 40 knots..
EHI is pretty impressive along the northern extent of the severe zone..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/03/00/NAM_221_2012070300_F24_EHI_3000_M.png
HELICITY is highest back into the Dakotas..
http://www.twisterdata.com/data/models/nam/221/maps/2012/07/03/00/NAM_221_2012070300_F24_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png
Due to this EHI we are going to place a 2% tornado chance back across the Montana region to the Dakotas also across all of MI and Wisconsin.. Otherwise heavy rains and Winds and hail will be the main threats!

Severe Weather Outlook for July 2nd

Severe Weather Outlook for July 2nd .. http://www.hpc.ncep.noaa.gov/basicwx/91fwbgus.gif At the surface... a cold front will be moving off the east coast with a warm front extending back westwards from the cold front.. As the cold front moves east further off the coast the warm front will be pushing northwards.. http://www.hpc.ncep.noaa.gov/basicwx/92fwbgus.gif By 18 Z low pressure will be located across the Dakotas http://www.hpc.ncep.noaa.gov/basicwx/93fwbgus.gif..It will be this frontal system that will once again serve as the focus for severe weather which is almost a carbon copy of the region from yesterday with some slight alterations in PA and the Northeast.. Looking at severe Parameters and temperatures. Well seems like a broken record being repeated but it is going to continue to be a hot day across vast majority of the country.. with high temperatures once again from 80 to the 100 degree or slightly above range.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F18_TMPF_2_M_ABOVE_GROUND.png ... In addition to being hot it will be sticky/humid with dew points in the 60-70 degree range http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F24_DPTF_2_M_ABOVE_GROUND.png ... CAPE or convective potential energy may be over done in the SE with a isolated locale showing up to 6000 but the minimum is 500..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F24_CAPE_SURFACE.png .... LIFT Index is 0 to about negative 10 depending on where you reside.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F24_PLI_30_0_MB_ABOVE_GROUND.png.. SHEAR is 30 to about 50 knots but kind of marginal across parts of the SE. These areas would be lower risk severe where as the higher or better chance of severe would be where the greater Shear is allocated. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F24_SHRM_500_MB.png ... ENERGY HELICITY index is greatest across the VA/ Carolina coast area and then up in the Midwest region.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/02/00/NAM_221_2012070200_F24_EHI_3000_M.png .. HELICITY the greatest areas are essentially the same as the EHI ...but the greatest is up in Minnesota. So from Wisconsin into Minnesota and Back into North Dakota we will place a 2 % chance of tornado's.. As well as in the eastern parts of VA, Carolina region ..Other wise the main threats will be winds, large hail and heavy rains!

Severe Weather Outlook for July 1st 2012

Severe Weather Outlook for July 1st 2012 ..Once again the temperatures across the outlook area are going to be on the warm to Hot side ..temperatures will be in the 80 to in the 100's range... So if you are out and about make sure you drink plenty of fluids.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F18_TMPF_2_M_ABOVE_GROUND.png .. In addition to the hot temperatures dew points will be in the 60s to 70s so it will feel hotter then it actually is.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_DPTF_2_M_ABOVE_GROUND.png .. Convective Potential Energy or CAPE is going to be from 500-4000 depending on where you are located.. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_CAPE_SURFACE.png.. LIFT Index will be from 0 to about negative 10 depending on where you are located .. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_PLI_30_0_MB_ABOVE_GROUND.png.. SHEAR is decent with 30 knots to around 50 knots .. http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_SHRM_500_MB.png .. ENERGY HELICITY INDEX is at 1 or above ..essentially the zone to watch would be from Indiana back towards Montana on a NW tracking..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_EHI_3000_M.png .. However HELICITY is not all that impressive across the region..http://www.twisterdata.com/data/models/nam/221/maps/2012/07/01/00/NAM_221_2012070100_F24_HLCY_3000_M_ABOVE_GROUND_0_M_ABOVE_GROUND.png ... We are going to place a 2% for tornados in the severe zone basically from Indiana NW tracking back into Montana.. At the surface ...http://www.hpc.ncep.noaa.gov/basicwx/91fwbgus.gif we essentially have a quasi stationary front... and this front along with impulses of energy moving across will serve as the trigger for the severe weather potential...